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Nano Material Applicationsin Fuel Cell
Dept. of Chemical Eng. Yonsei Univ.Prof. Y.G. Shul, H.S. Kim

Nano Materials in Fuel Cell
Hydrogen Release Catalyst Novel Anode Catalyst
Organic-Inorganic Membrane

Fuel Cell Applications
Heteropolyacid(HPA)-SiO2 nanoparticles for high temperature operation of a direct methanol fuel cell
Preparation and characterization of new carbon for fuel cell application
Pulse Electrodeposition for Preparing PEM Fuel Cell Electrode
Investigation of alloy catalyst for accelerating hydrogen release from NaBH4

In this study
SiO2
Heteropoly acid
Nano scale. .. ...... .
.... .
.. .. ...... .
.... .
.
. .. ...... .
.... .
.. .. ...... .
.... .
.. .. ...... .
.... .
.. .. ...... .
.... .
.
. .. ...... .
.... .
.. .. ...... .
.... .
.. .. ...... .
.... .
.. .. ...... .
.... .
.
Preparation nanohybride particle (HPA/SiO2)By micro emulsion technique
Characterization :TEM, Solid state NMR, TMP adsorption, N2 adsorption, FT-IR

Heteropolyacid-SiO2 nanoparticles
TEM image of heteropolyacid-SiO2 nanoparticle(R=2, HPA 30%, 24hr)
TEM image of heteropolyacid-SiO2 nanoparticle(R=2, X=30%, 12hr)
100 nm 100nm
R= [H2O]/[AOT]X=[Heteropolyacid]

31P MAS NMR
Chemical shift (, ppm)
-20-18-16-14-12-10
Heteropolyacid
100nm
500nm
Bulk
Dehydration
Fig. 31P MAS NMR spectra of heteropolyacid and HPA/SiO2
H3PW12O406H2O
-15.6ppm
-15.3ppm
-15.1ppm
-15.0ppm
Referenced from- M.Misono et al., J.Phys.Chem.B., 104 (2000) 8108- F.Lefebvre et al., J.Chem.Soc.Chem.Commun, (1992) 756
Dehydration of heteropolyacid
Heteropolyacid < nanoparticle < Bulk powder
Trapping of acidic proton to OH group
Si
OHH+
Si
OHH+
Si
OHH+
34012 ][ OPW

13C CP MAS NMR
13C CP MAS NMR spectra (a) thiol- and (b) sulfonic-functionalized heteropolyacid-SiO2 nanoparticle.
0102030405060
(a)
(b)
27.9 ppm
11.4 ppm18.2 ppm
54.0 ppm
0102030405060
(a)
(b)
27.9 ppm
11.4 ppm18.2 ppm
54.0 ppm

Preparation of inorganic particles in microemulsion
H2OHPA
CyclohexaneTEOS
Si(OR)4 + 4H2O Si(OH)4 + 4ROH
Si-OH + HO-Si Si-O-Si + H2O
Sol-gel process
O
O
O
O
SO3-
Na+
Aerosol-OT

Surface area vs. nano HPA/SiO2
Pore size (A)0 20 40 60 80
DV/
DR
(cm
3 /g)
0.00
0.01
0.02
0.03
0.04
0.05
100nm HPA/SiO2500nm HPA/SiO2Bulk HPA/SiO2
1 2 3
Por
e fra
ctio
n
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1 2 3 4
BET
Surfa
ce a
rea
(m2 /g
)
0
100
200
300
400
500
600
Surface area Pore size distribution
HPA 100nm500nmBulk
Pore ratio
R > 3nm
100nm500nmBulk
R < 1nm

Application to DMFC
Pressure gauge
Methanol2M solution.
Fuel pump
Fuel heater
Cell
Needlevalve
flowmeter
2wayvalve
O2
Tank
G.C
6 wayvalve
Pressure gauge
Methanol2M solution.
Fuel pump
Fuel heater
Cell
Needlevalve
flowmeter
2wayvalve
O2
Tank
G.C
6 wayvalve
Heteropolyacid
Proton conductivity
Silica particle
Methanol blocker

Polysulfone/nanoparticle composite membrane
45 50 55 60 65 70 75 80 85 90 95 100 105 1100
20
40
60
80
100
Z''(o
hm)
Z'(ohm) Cell temperature (oC)
20 40 60 80 100 120 140
Met
hano
l cro
ssov
er ra
te
(m
ol /
cm2 m
in)
0
2
4
6
8
10
12
14
16
18
Sulfonated polysulfone membraneComposite membrane
Heteropolyacid-SiO2 nanoparticle
Heteropolyacid-SiO2 nanoparticle
1.4 10-3 S/cm 6.510-5 S/cm
Complex impedance response(a) and methanol crossover rate(b) of the sulfonated polysulfone and sulfonated polysulfone / heteropolyacid SiO2 nanoparticle composite membrane.
(a) (b)

Nafion/nanoparticle composite membrane
Content of nanoparticles (%)
0 5 10 15 20 25
cond
uctiv
ity x
102 (
S/cm
)
0
2
4
6
8
10
Temperature (oC)
0 20 40 60 80 100 120 140 160C
ross
over
rate
( m
ol/c
m2 *
min
)0
20
40
60
80
100
Nafion membraneComposite membrane
Proton conductivity(a) and methanol crossover rate(b) of the sulfonated polysulfone and sulfonated polysulfone / heteropolyacid SiO2 nanoparticle composite membrane.
(a) (b)
Reduction of methanol crossover
A little decrease of proton conductivity

Nafion-HPA/SiO2 composite membrane
Current density (mA/cm2)
0 50 100 150 200 250 300
Cel
l vol
tage
(V)
0.0
0.2
0.4
0.6
0.8
80 oC160 oC200 oC
Pow
er d
ensi
ty (m
W/c
m2 )
0
10
20
30
40
50
60
Wavenumber (cm-1)
1000150020002500300035004000
Tran
smitt
ance
(%)
0
20
40
60
80
100
Heteropolyacid - SiO2 nanoparticleSulfonated heteropolyacid - SiO2 nanoparticle
FT-IR spectra of sulfonated heteropolyacid-SiO2 nanoparticle
(Nafion / sulfonated heteropolyacid-SiO2 nanoparticle composite membrane)
H2O H3O+
DMFC performance of composite membrane
Improvement of DMFC performance by increasing the cell temperature

Research of carbon material application
Caron structure
FC application
Performance remark Reference
Pt/CNT PEMFC 0.7V, 0.7 mA/cm2
(50oC)
high electrocatalytic activity for oxygen reduction3.60.3nm
J.of power sources
139(2005) 73
Pt/mesoporous carbon(SBA-15)
DMFC 0.4V, 135 mA/cm2 (65oC)
Great potentiality for DMFC supportJohnson Mattheyat
0.4V, 135 mA/cm2 (80oC)
J.Of power sources
130 (2005)
PtSn/MWNT
DEFC 0.4V, 100 mA/cm2
Improvement in liquid mass transfer for catalyst-3nm
PtSn/XC-720.4V, 80 mA/cm2
Carbon 42(2004)
Carbon fiber
Mg-H2O2Semi-fuel
cell
1.5V,300mA/cm2
Similar reference with Pt-Ir on carbon paperMg: anode
Microfiber carbon :cathodecathode side: 0.20M H2O2
J.Of power sources 96 (2001) 240
Carbon nanocoil
DMFC 0.4V , 170mA/cm2
(60oC)
Great potentiality for DMFC support material Angew. Chem2003,115,
4488
Carbon nanohorn
DMFC 0.4V , 130mA/cm2
NEC

I-V curve for electrodes with commercial Pt/C and Pt/C+ Pt/ACF (900)
Current density ( A/cm2 )
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4
Volta
ge (
V )
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
Commercial Pt/CCommertial Pt/C (70%)+ Pt/ACF(30%.400oC)Commertial Pt/C (70%)+ Pt/ACF(30%.900oC)
Performance increasing
Commercial Pt/C Pt/C+Pt/ACF (400) Pt/C+Pt/ACF (900)
Current density ( mA/cm2 ) 710 807 960
Cell Temp. : 80, Humidify condition : RH% 100 anode and cathode, Flow rate: Stoichiometry 1.5(Anode):2.0(Cathode)

Impedance for the electrodes manufactured with Pt/C, Pt/ACF(900) catalysts
Z' / Ohm
0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26
-Z''
/ O h
m
0.00
0.02
0.04
0.06
0.08
0.10
Pt/ACF ( 400oC )Pt/ACF ( 900oC )
Z' / Ohm
0.0 0.1 0.2 0.3 0.4 0.5-Z
'' / O
hm
0.00
0.05
0.10
0.15
0.20
0.25
0.30
Pt/ACF ( 400oC )Pt/ACF ( 900oC )
Impedance spectra at 0.8VImpedance spectra at 0.7V

Specific surface area and average pore diameter of the CNF treated by KOH
58.01303.54950-1h
62.37341.87900-3h
54.41375.52Modified method
44.33460.10900-2h
48.0645.53900-1h
48.80509.95800-1h
46.07444.18750-1h
62.21107.60No activation
5H
Avg. Pore diameter( )
Surf. area(m2 /g)
Activation conditionCNF
58.01303.54950-1h
62.37341.87900-3h
54.41375.52Modified method
44.33460.10900-2h
48.0645.53900-1h
48.80509.95800-1h
46.07444.18750-1h
62.21107.60No activation
5H
Avg. Pore diameter( )
Surf. area(m2 /g)
Activation conditionCNF

SEM - CNFs named 5H
pristine
MDF(900-2h)
800-1h
900-2h

TEM - 60wt% Pt-Ru/CNF
50 nm 50 nm 50 nm
(a) (b) (c)A/(900-2h) B/(900-2h) B/MDF(900-2h)

Growth of nanofiber on ACF
micropores
Surface and Pores of Activated Carbon Fiber
Reduction in He/H2
Synthesis from C2H4/H2
a
b a, b
c
inactive
H2 C2H4
Impregnation of metal salt solution

Preparation of various carbon substrates
CNF/ACF
Fig. SEM images of carbon nano fibers grown on ACFFig. SEM images of carbon nano fibers grown on AC

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